using OrdinaryDiffEqLowStorageRK
using Trixi

###############################################################################
# semidiscretization of the Lattice-Boltzmann equations for the D2Q9 scheme

equations = LatticeBoltzmannEquations2D(Ma = 0.1, Re = Inf)

initial_condition = initial_condition_constant

solver = DGSEM(polydeg = 3, surface_flux = flux_godunov)

coordinates_min = (-1.0, -1.0)
coordinates_max = (1.0, 1.0)
mesh = TreeMesh(coordinates_min, coordinates_max,
                initial_refinement_level = 4,
                periodicity = true)

semi = SemidiscretizationHyperbolic(mesh, equations, initial_condition, solver;
                                    boundary_conditions = boundary_condition_periodic)

###############################################################################
# ODE solvers, callbacks etc.

tspan = (0.0, 1.0)
ode = semidiscretize(semi, tspan)

summary_callback = SummaryCallback()

analysis_interval = 100
analysis_callback = AnalysisCallback(semi, interval = analysis_interval)

alive_callback = AliveCallback(analysis_interval = analysis_interval)

save_restart = SaveRestartCallback(interval = 100,
                                   save_final_restart = true)

save_solution = SaveSolutionCallback(interval = 100,
                                     save_initial_solution = true,
                                     save_final_solution = true,
                                     solution_variables = cons2macroscopic)

stepsize_callback = StepsizeCallback(cfl = 1.0)

collision_callback = LBMCollisionCallback()

callbacks = CallbackSet(summary_callback,
                        analysis_callback, alive_callback,
                        save_restart, save_solution,
                        stepsize_callback,
                        collision_callback)

###############################################################################
# run the simulation

sol = solve(ode, CarpenterKennedy2N54(williamson_condition = false);
            dt = 1, # solve needs some value here but it will be overwritten by the stepsize_callback
            ode_default_options()..., callback = callbacks);
